Electric switch mechanism



March 1s, 1sa30. w, K, RANKIN 1,751,420

ELECTRIC SWITCH MECHANISM Filed March 25, 1927 M-11 UVEI TL 0A0 TRIPFig. I.

Invenfor- Vfiliiam K. Rankin, by M Hi5 AITorne g Patented Mar. 18, 1930PATENT orrlcs WILLIAM K. RANKIN, F SCOTIA, NEW YORK, ASSIGNOR PANY, ACORPORATION OF NEW r0 GENERAL ELECTRIC com- YoBx ELECTRIC swrrcnMECHANISM Application filed March 25,

My invention relates to electric switch mechanism and particularly tothat type of switch mechanism which is especially adapted for thecontrol of modern commercial power circuits of large capacity and whichcomprises a plurality of similar switches adapted for simultaneousoperation and provided with individual operating mechanisms.

Switch mechanism of the type referred to,

for example, three-phase switch mechanism,

has commonly been constructed with mechanical operating connectionsbetween the separate phase switch units, which connections had theeflect of insuring simultaneous and equal movements of the movingcontacts of the several switch units. Where individual operatingmechanisms without mechanical interconnections are employed for theseveral switchunits, there is the danger that,

from one cause or another, the several oper ating mechanisms may notcause their respective switch units to close at the same tune, or one ormore of the units may even fail to be closed at all. There is also theadded danger, in the event of one switch unit failing to close, of themechanism maintaining the other switch units closed and therebycontinuing an unbalanced condition on the circuits controlled by theswitch mechanism. It is an object of my invention, therefore, to providean improved switch mechanism which will to a large degree, if notentirely, avoid the dangers mentioned above, together with otheradvantages which will appear from the description which follows.

Briefly, in accordance with my invention,

I employ a plurality of separate switch units,

each having its own separate operating mechanism, and associated withthe several operating mechanisms I provide mean which automaticallybecomes effective to render the operating mechanism inoperative in theevent that the several mechanisms fail to keep to"- gether in theirclosing movement or that one or'more mechanisms fail to start. I alsoprovide means for operating the unlatching or tripping means of theseveral switch units after a predetermined time interval in the eventthat any switch unitfails to become- 50 latched in closed circuitposition.

1927. Serial No. 178,427.

My invention will be better understood from the following descriptiontaken in connection with the accompanying drawing, and its scope will bepointed out in the appended claims.

Referring to the drawing, Fig. 1 is a diagrammatic view of apparatus andcircuit connections illustrating one embodiment of my invention; andFig. 2 is a detail.

In the drawing, I have shown at 1, 2 and 3 parts of three similar switchunits, each having an operating rod 4 and each. having a separateoperating'mechanism 5. The switch units 1, 2, 3 may, for example, bephase switches of a three-phase switch installation, and theinstallation also may be of the isolated-phase type, in which case theseveral units and their mechanisms would be spaced or suitably isolatedfrom one another. While I have illustrated the units as arrangedhorizontally, it will be understood that they may be arranged verticallyif desired, or in any other manner that may be found desirable. Theparticular type of switch unit which I have chosen to illustrate issimilar to that disclosed in Letters Patent 1,133,032, Jacobs, March 23,1915, the movable contacts of which are carried bythe operating rods 4,and are given a downward movement to close the switch and an upwardmovement to open the same.

The several operating mechanisms 5 are identical in construction andoperation; hence, but one will be described in detail, thisv one beingrepresentative of all three illustrated. The link and lever mechanism 7for producing a straight line movement of the operating rod 4 may beconstructed in any well-known manner, the particular arrangement beingimmaterial in the present. example, and is shown as operated by thecrank 8 on shaft 9. The shaft, which in the open circuit position of theswitch has its crank 8 standing upright, is given a rotary movement ofapproximately one half turn by the ,energization of the solenoid 10whose plunger 11 is connected with the shaft through the gear 12 andrack 13. Also mounted on shaft 9 is the cam 14 having a concentric facewhich terminates at one end in the shoulder 15.

The cam 14 and cooperating arm 16 pivoted at 17 constitute the means forlatching-in the switch in closed circuit position, the arm' beingprovided with a shoulder 18 which when the mechanism reaches closedcircuit position drops over the shoulder 15 of the cam and retains themechanism. The free end of the arm 16 is shown having an extension 19terminating in switch contacts 20 which engage one or the other of theopposed fixed contacts 21 and 22, which contacts are arranged in pairs.For raising the arm 16 to release the latch and to allow the switch toopen, I have provided the solenoid or trip coil 23 and the cooperatingplunger 24, an extension of which forms a hook 25 to engage beneath andto raise the arm 16. Carried also by the plunger 24 is a cross memberhaving contacts which disengage the fixed contacts 26 when the plungeris raised. Coil spring 28 serves to return the shaft to its open circuitposition. Mounted on the shaft 9 is the circuit controller 30 comprisinga drum having a double set of contact plates on its face, as shown moredistinctly in Fig. 2. Each set of contact plates comprises a long plate31 connected to the shorter plates 32, 33 and 34. Of these plates, plate32 is shown very short for a reason to be explained later. Brushes 35,shown for convenience as arrows, are arranged in a row to bear againstthe cylinder so as to contact with their respective plates as the drumrotates.

The main contactor 37 with which the closing solenoids 10 are connectedin series is moved to closed position by the solenoid 38 and in circuitwith the solenoid is the winding of the time delay relay 39, the thermalcut-out 40 and the manual switch 41. The latter is shown as of thepull-button type having the movable contact 42 which when the switch isoperated is drawn first between the pivoted contacts 43 to close thecircuit of solenoid 38 and then by its continued movement is releasedfrom contacts 43 and is drawn between contacts 44 in the sealing-incircuit including the contactor 37 Contacts 43 are covered withinsulation on their rear faces so'that when contact 42 is allowed toreturn, the circuit through solenoid 38 having been interrupted will notbe reclosed. The hand trip 47 the overload trip 48 and the time delayrelay 39 are arranged in parallel, any one of which closes the circuitof the trip coils 23. Suitable green and red signal lamps G and R areshown connected in the control circuit so as to be illuminatedrespectively when the main switch is in open position, as illustrated,and in closed position.

With the parts in the position illustrated, to close. the switch units1, 2 and 3 the pull switch 41 is operated, drawing the contact 42through the contacts 43 into engagement with the contacts 44. Thecircuit of solenoid 38 is thus closed, being completed through thewinding of the time delay relay 39, the contacts 32 and 31 of thecontrollers 30 in series and contacts 20, 22 of the several operatingmechanisms in parallel. Closing of the contactor 37 causes theenergization of each of the switch closing solenoids 10. The shafts 9are rotated thereby simultaneously for approximately 180 degrees, andthrough the mechanisms 7 the respective switches 1, 2 and 3 are closed.If the three mechanisms start movement together and continue to keeptogether, the controller contacts 32, 33

and 34 of the several controllers will make corresponding andsimultaneous changes in the circuit connections at the severalcontrollers, and the circuit of solenoid 38 will remain closed. If,however, one of the mechanisms should fail to start with the rest, itsshort contact 32 would still be in a position to engage a correspondingfixed contact 35, while the controller of another mechanism would haveadvanced so as to bring the next contact 33 into engagement with acorresponding fixed contact, thus interrupting the circuit of solenoid38 and allowing the contactor to open. The operating solenoids 10 beingdeenergized, the switches return to then original position, the presenceof the green light G and the absence of the red light R indicating tothe operator that for some reason the switch has failed to close. In asimilar manner it the several mechanisms havin started oil together failto keep together in t eir closing movement, the controller contacts 33and 34 will not pass under the fixed contacts simultaneously at theseveral mechanisms and thus will interrupt the circuit of the solenoid38. For convenience in the disclosure I have shown the controllershaving but three segment contacts 32, 33 and 34, but it will beunderstood that a greater number may be used if desired. As each switchmechanism reaches its closed circuit it is latched in by the arm 16dropping over the shoulder 15 of the cam 14. This movement separatescontacts 20 and 22. Since these contacts of the several mechanisms areconnected in parallel to the circuit of solenoid 38, the solenoid ,willbe open-circuited when and only when all three mechanisms have beenlatched closed. If for example one mechanism fails to operate its switchsuficiently far to become latched in, the contactor 37 will remainclosed until the switch 41 is released or the time delay relay 39operates to close the circuit of the trip coils 23 whereby all three ofthe switch operating mechanisms are tripped to open-circuit position.Tripping of the mechanisms is also produced by the operation of theoverload responsive device 48 or by the hand switch 47, and signal lampsG and R are lighted respectively when the mechanisms are in theopen-circuit position illustrated and in latched-in closed-circuitposition, the latter lamp being controlled by the contacts 20 and 21.

If desired, the controller contacts 32, 33 and 34 may overlap slightlyto allow slight permissible diflerences in the relative positions of themechanisms Without causing the deenergization of the closing solenoids.I prefer. however, to construct the contactor solenoid 38 so as to havea time lag such that the contactor will open only when theabovementioned permissible difierence is exceeded.

I have chosen the particular embodiment described above as illustrativeof my invention, and it will be apparent that various modifications maybe made Without departing .from the spirit and scope of my invention,which modifications I aim to cover by the appended claims.

What I claim as new, and desire to secure by Letters Patent of theUnitedStates, is:

1. An electric switch comprising a plurality of switch units, eacharranged to control a separate main circuit conductor, similarindividual operating mechanisms for said units adapted simultaneously tooperate the same, and means cooperatively related to said mechanisms andoperative in response to the failure of said mechanisms to move togetherfor rendering all of the mechanisms inoperative.

2. An electric switch comprising a plurality of similar switch units,separate operating mechanisms for moving the respective switch units toclosed=circuit position, separate latching-in means for holding therespective mechanisms in closed-circuit position, means for releasingthe latching-in means, and means including a time delay device forcausing the operation of the releasing means if less than the fullmember of mechanisms are latched in.

3. A switch for a polyphase system comprising separate switch units forcontrolling the individual phases of said system, a separate operatingmechanism for each unit, each mechanism having a plurality of pairs ofrelatively movable contacts arranged during the closing movement of themechanisms to successively close a plurality of circuits, and

means responsive to the simultaneous closing of corresponding circuitsat the several mechanisms for controlling the closing movement of all ofthe mechanisms.

4:. A switch for a polyphase system comprising separate switch units forcontrolling the individual phases of said system, a separate electricoperating mechanism for each unit, a common supply circuit therefor, acircuit controller drum associated with each mechanism and rotatedthereby, a plurality of brushes engaging each drum, connections betweenthe brushes of the respective drums whereby a continuous current flow ismaintained through a plurality of successive series circuits in responseto substantially equal rotative movements of the several drums, andmeans for interrupting said common supply circuit in response to aninterruption in said current flow resulting from an unequal movement ofsaid drums.

5. A switch for a polyphase system comprising a plurality of switchunits arranged to control the individual phases of said system, separateelectrically energized operating means for each unit, said means beingadapted to operate in unison, and means for causing the deenergizationof all of said operating means in response to unequal movements of saidoperating means.

6. A switch for a polyphase system comprising a plurality of switchunits for controlling the individual phases of said system, separateoperating mechanisms for the respective units, electrical means formoving the operating mechanisms in unison, and means responsive to adifference in the 1mtial movements of the several mechanisms for causingthe deenergization of said electrical means.

7. A switch for a polyphase system comprising a plurality of similarswitch un ts for controlling the individual phases of said system,separate mechanisms for operating the respective units, electromagneticactuating means for producing synchronousmovements of said mechanisms,and circuit con trolling means responsive to a lack of synchronism inthe movements of the mechanisms for deenergizing the actuating means.

In witness whereof, I have hereunto set my hand this 24th day of March,1927.

WILLIAM K. RANKIN.

